Radio communication system, communication apparatus, radio communication network system and method therefor

ABSTRACT

A radio communication system provided with a communication device and a radio communication network system is characterized by comprising a transmission delay estimate information transmitting means for transmitting transmission delay estimate information to the radio communication network system when the transmission condition of the transmission delay estimate information is met.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. application Ser. No.16/879,302, filed May 20, 2020, which is a Continuation of U.S.application Ser. No. 16/418,309, filed May 21, 2019, issued as U.S. Pat.No. 10,701,736 on Jun. 30, 2020, which is a Continuation of U.S. patentapplication Ser. No. 15/904,762, filed Feb. 26, 2018, issued as U.S.Pat. No. 10,356,822 on Jul. 16, 2019, which is a Continuation of U.S.patent application Ser. No. 15/424,022, filed Feb. 3, 2017, issued asU.S. Pat. No. 9,986,589 on May 29, 2018, which is a ContinuationApplication of U.S. patent application Ser. No. 13/674,248, filed Nov.12, 2012, issued as U.S. Pat. No. 9,603,103 on Mar. 21, 2017, which is aDivisional of U.S. patent application Ser. No. 12/920,443, filed Aug.31, 2010, issued as U.S. Pat. No. 9,338,752 on May 10, 2016, which is anational stage of International Application No. PCT/JP2009/054171, filedMar. 5, 2009, claiming priority based on Japanese Patent Application No.2008-057726, filed Mar. 7, 2008, the contents of all of which areincorporated herein by reference in their entirety.

APPLICABLE FIELD IN THE INDUSTRY

The present invention relates to a radio communication system, acommunication apparatus, a radio communication network system, and amethod therefor.

BACKGROUND ART

A transmission power of RACH (Random Access Channel) in 3GPP UMTS/LTE isdecided based upon a power offset designated by a base station or afixed power value common to one cell. However, the base station cannotrecognize that one mobile station has tried to make a connection to thebase station over the RACH until the base station receives the RACHcorrectly. For this, when the base station is not able to correctlyreceive the RACH coming from the mobile station, the transmission powercannot be adaptively controlled according to the situation oftransmission of the RACH from the mobile station to the base station.

Thereupon, the technology in which the mobile station transmitstransmission delay estimation information on the RACH together with apreamble or data and the base station decides a designation value forsetting the transmission power of the RACH according to the transmittedtransmission delay estimation information is proposed (Patent document1). Additionally, the transmission delay estimation information is thenumber of times of transmission or the number of times of retransmissionof the data or the preamble, a time elapsed since initial transmissionof the data or the preamble, a timing of the initial transmission of thedata or the preamble, or the like. Additionally, the so-called preambleis a bit pattern known to the base station, and a signal unknown to thebase station such as user data or a control signal is not transmitted asthe preamble.

Hereinafter, the case of applying the technology of the Patent document1 related to the present invention to an E-UTRA system now underconsideration in the 3GPP will be explained.

FIG. 22 is a conceptual diagram of the system to which the Patentdocument 1 related to the present invention is applied. In the system ofthe technology of the Patent document 1, a plurality of the base stationare present adjacently to one another, a plurality of the mobilestations transmit or receive data on a downlink or an uplink to or fromeach of the base stations, OFDM (Orthogonal Frequency Division MultipleAccess) is used for the downlink, and SC-FDMA (Single-Carrier FrequencyDivision Multiple Access) is used for the uplink. Furthermore, each ofthe mobile stations and base stations realize functions to be describedbelow by a control program stored in a memory of each of the mobilestations and base stations.

Each base station transmits on the downlink at least a broadcast channel(BCH) for transmitting broadcast information such as system information,a common pilot channel (CPICH) for transmitting a pilot signal, and acommon channel (AICH: Acquisition Indicator Channel) for transmitting anacknowledgment signal (ACK signal) in response to uplink datatransmission.

FIG. 23 is a sequence diagram illustrating one example of an operationof the above-mentioned system.

One mobile station transmits or receives data based upon the systeminformation transmitted over the BCH, receives the CPICH in apredetermined cycle to ensure synchronization, and measures a receptionpower of the CPICH (step 1-1). And, the mobile station transmits thepreamble over a random access channel (RACH) RACH-1 based upon RACHtransmission power information notified over the BCH and a CPICHreception power (Step 1-2).

Herein, when the base station cannot detect the RACH-1, the base stationtransmits NACK over the AICH without transmitting the ACK (Step 1-3).

Then, the mobile station transmits RACH-2 by increasing the transmissionpower by a power ramping step size that is included in the RACHtransmission power information (Step 1-4).

The base station, upon detecting the RACH-2, transmits the ACK (Step1-5).

The mobile station, upon receipt of the acknowledgment (afterreceiving), transmits the transmission delay estimation information overa RACH message part (Step 1-6).

The base station modifies the RACH transmission power information of theBCH based upon the transmission delay estimation information, andtransmits it (Step 1-7).

FIG. 24 is a sequence diagram illustrating an example of anotheroperation in the above-mentioned system.

One mobile station transmits or receives data based upon the systeminformation transmitted over the BCH. Further, the mobile stationreceives the CPICH in a predetermined cycle to ensure synchronizationand measures a reception quality of the CPICH (Step 2-1).

When user data or a control signal to be transmitted occurs to themobile station, the mobile station transmits the transmission delayestimation information using a random access channel (RACH) that is oneof uplink wireless channels (Step 2-2). A RACH transmission power atthis time is decided based upon a value indicated by the base stationusing the BCH.

When the base station cannot detect the RACH of the mobile station, thebase station does not transmit the ACK over the AICH (Step 2-3).Further, when the base station detects the RACH, the base stationtransmits the ACK over the AICH (Step 2-5).

When the mobile station transmits the preamble over the RACH, the mobilestation receives the random access response over the AICH after apredetermined time, and retransmits the transmission delay estimationinformation at a predetermined timing until the mobile station receivesan acknowledgment signal (ACK signal) indicating that the preambletransmitted by its own station has been correctly received (Step 2-4).

Performing such a process enables the base station to controlinformation on the RACH transmission power indicated by the BCH so thata delay required until the data or the preamble, which is transmittedover the RACH, is correctly received is controlled to an appropriatevalue, and to reduce interference by setting the transmission power ofthe mobile station as low as possible while effectively reducing thedata transmission delay.

Patent document 1: Publication number: WO2007/052753

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention

In the related technology mentioned above, all of the mobile stations,which transmit the RACH, transmit the transmission delay estimationinformation.

However, the related technology necessitates a lot of wireless resourcesbecause all of the mobile stations transmit the transmission delayestimation information. In particular, transmitting the transmissiondelay estimation information together with the preamble leads toexcessive consumption of the wireless resources because the mobilestation transmits the transmission delay estimation information alsowhen the RACH is not detected.

Thereupon, the present invention has been accomplished in considerationof the above-mentioned problems, and an object thereof is to provide aradio communication technology of transmitting the transmission delayestimation information while reducing the consumption of the wirelessresources.

Means to Solve the Problem

The present invention for solving the above-mentioned problems is aradio communication system comprising a communication apparatus and aradio communication network system, wherein the communication apparatuscomprises a transmission delay estimation information transmission unitfor transmitting transmission delay estimation information to the radiocommunication network system when a transmission condition oftransmission delay estimation information is met.

The present invention for solving the above-mentioned problems is acommunication apparatus, comprising a transmission delay estimationinformation transmission unit for transmitting transmission delayestimation information to a radio communication network system when atransmission condition of transmission delay estimation information ismet.

The present invention for solving the above-mentioned problems is aradio communication network system in a communication system fortransmitting transmission delay estimation information when acommunication apparatus meets a transmission condition of thetransmission delay estimation information, said radio communicationnetwork system comprising a common control unit for causing thecommunication apparatus to commonly transmit the transmission delayestimation information.

The present invention for solving the above-mentioned problems is aradio communication method, wherein a communication apparatus transmitstransmission delay estimation information to a radio communicationnetwork system when a transmission condition of the transmission delayestimation information is met.

An Advantageous Effect of the Invention

The present invention makes it possible to reduce the wireless resourcesfor transmitting the transmission delay estimation information ascompared with the case of the convention art.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram for explaining an outline of the present invention.

FIG. 2 is a specific configuration diagram of a radio communicationnetwork system 1 and communication apparatuses 2 ₁ to 2 ₃.

FIG. 3 is a specific configuration diagram of the radio communicationnetwork system 1 and the communication apparatuses 2 ₁ to 2 ₃.

FIG. 4 is a specific configuration diagram of the radio communicationnetwork system 1 and the communication apparatuses 2 ₁ to 2 ₃.

FIG. 5 is a conceptual diagram of the system to which the presentinvention is applied.

FIG. 6 is a configuration diagram of the mobile station in thisembodiment.

FIG. 7 is a configuration diagram of the base station in thisembodiment.

FIG. 8 is a sequence diagram in the case of commonly applying atransmission delay estimation information transmission condition to allof the mobile station.

FIG. 9 is a sequence diagram in the case of separately/selectivelyapplying the transmission delay estimation information transmissioncondition to the mobile stations.

FIG. 10 is another sequence diagram in the case of commonly applying thetransmission condition of the transmission delay estimation informationto all of the mobile station.

FIG. 11 is an operational flowchart of the mobile station in thisembodiment.

FIG. 12 is another operational flowchart of the mobile station in thisembodiment.

FIG. 13 is a diagram for explaining a correspondence between eachchannel of this embodiment and each channel of the 3GPP LTE system.

FIG. 14 is a diagram for explaining an example 1.

FIG. 15 is a diagram for explaining an example 2.

FIG. 16 is a diagram for explaining an example 3.

FIG. 17 is a diagram for explaining an example 5.

FIG. 18 is a diagram for explaining an example 5.

FIG. 19 is a diagram for explaining an example 6.

FIG. 20 is a diagram for explaining an example 6.

FIG. 21 is a diagram for explaining an example 6.

FIG. 22 is a conceptual diagram of the system to which the Patentdocument 1 related to the present invention is applied.

FIG. 23 is a sequence diagram of the system to which the Patent document1 is applied.

FIG. 24 is another sequence diagram of the system to which the Patentdocument 1 is applied.

DESCRIPTION OF NUMERALS

-   -   1 radio communication network system    -   2 ₁ to 2 ₃ communication apparatuses    -   11 reception processing unit    -   12 signal separation unit    -   13 pilot signal measurement unit    -   14 transmission power calculation unit    -   15 acknowledgment signal determination unit    -   16 transmission delay estimation information generation unit    -   17 buffer    -   18 signal combining unit    -   19 transmission processing unit    -   20 transmission determination unit    -   21 reception processing unit    -   22 decoding unit    -   23 error determination unit    -   24 signal separation unit    -   25 transmission delay estimation unit    -   26 power offset control unit    -   27 control signal generation unit    -   28 signal combining unit    -   29 transmission processing unit

BEST MODE FOR CARRYING OUT THE INVENTION

An outline of the present invention will be explained.

FIG. 1 is a diagram for explaining an outline of the present invention.

As shown in FIG. 1 , communication apparatuses 2 ₁ to 2 ₃ are managed bya radio communication network system 1. While conventionally, all of thecommunication apparatuses 2 ₁ to 2 ₃, which transmitted the RACH,transmitted the transmission delay estimation information to the radiocommunication network system 1, each of the communication apparatuses 2₁ to 2 ₃ transmits the transmission delay estimation information to theradio communication network system 1 when it meets the transmissiondelay estimation information transmission condition in the presentinvention.

Herein, upon paying attention to a specific configuration of the radiocommunication network system 1 and the communication apparatuses 2 ₁ to2 ₃, for example, with the case of the 3GPP, the radio communicationnetwork system 1 corresponds to RNC (Radio Network Controller) and BTS(Base Transceiver Station), and the communication apparatuses 2 ₁ to 2 ₃corresponds to MS (Mobile Station) as shown in FIG. 2 . Further, theradio communication network system 1 corresponds to eNode-B, and thecommunication apparatuses 2 ₁ to 2 ₃ correspond to UE (User Equipment)in some cases. Further, the radio communication network system 1corresponds to CN (Core Network) and eNode-B, and the communicationapparatuses 2 ₁ to 2 ₃ correspond to UE (User equipment) in some cases.

With the case of WiMAX, the radio communication network system 1corresponds to BS (Base Station), and the communication apparatuses 2 ₁to 2 ₃ correspond to MS (Mobile Station) as shown in FIG. 3 . Further,the radio communication network system 1 corresponds to ASN GW (AccessService Network Gate Way) and BS (Base Station), and the communicationapparatuses 2 ₁ to 2 ₃ correspond to MS (Mobile Station) in some cases.Further, the radio communication network system 1 corresponds to CSN(Connectivity Service Network) and ASN (=ASN+BS), and the communicationapparatuses 2 ₁ to 2 ₃ correspond to MS (Mobile Station) in some cases.

With the case of wireless LAN, the radio communication network system 1corresponds to AP (Access Point), and the communication apparatuses 2 ₁to 2 ₃ correspond to WT (Wireless Terminal) as shown in FIG. 4 .Further, the radio communication network system 1 corresponds to Serverand AP (Access Point), and the communication apparatuses 2 ₁ to 2 ₃correspond to WT (Wireless Terminal) in some cases.

Additionally, in the following explanation, the radio communicationnetwork system 1 is defined as the base station, and each of thecommunication apparatuses 2 ₁ to 2 ₃ is defined as the mobile station.

Herein, upon paying attention to a timing at which the transmissiondelay estimation information transmission condition is collated, asdescribed in the related art, the transmission delay estimationinformation transmission condition may be collated irrespective of thereception of the acknowledgment signal when the access signal (the data,the preamble, or the like) is transmitted, and the transmission delayestimation information transmission condition may be collated after theacknowledgment signal is received, and further the timing of thecollation is not limited hereto. That is, the transmission delayestimation information is transmitted when the transmission delayestimation information transmission condition is met in the system oftransmitting the transmission delay estimation information in the caseof transmitting the access signal (the data, the preamble, or the like)irrespectively of the acknowledgment signal. Further, the transmissiondelay estimation information is transmitted after it is determined thatthe acknowledgment signal has been received, and yet when thetransmission delay estimation information transmission condition is metin the system of transmitting the transmission delay estimationinformation after receiving the acknowledgment signal.

Further, the so-called the transmission delay estimation information is,for example, the number of times of transmission or the number of timesof retransmission of the access signal (the data, the preamble, or thelike), a time elapsed since the initial transmission of the accesssignal, a timing of the initial transmission of the access signal, aback-off period required for transmitting the access signal, a valueobtained by deducting the back-off period from a period required fortransmitting the access signal, the number of times of power rampingrequired for transmitting the access signal, the number of times ofpower ramping cycle required for transmitting the access signal, or thelike.

Additionally, the above-mentioned value of the transmission delayestimation information could be an actual value itself, and a tableindicative of an index corresponding to a threshold is prepared inadvance and the value of the transmission delay estimation informationmay be notified by use of the above index.

Further, the so-called transmission delay estimation informationtransmission condition is a condition associated with the number oftimes of retransmission or the number of times of transmission of theaccess signal required until the confirmation response to transmissionof the above access signal from the communication apparatus to the radiocommunication network system is received, a time elapsed until theconfirmation response to transmission of the above access signal isreceived, a transmission power of the above access signal, a path lossor a reception quality of the signal from the radio network system tothe communication apparatus, a probability of a target to which thetransmission delay estimation information is transmitted, identificationinformation of the communication apparatus, a traffic of the aboveaccess signal, an application of the above access signal, a time elapseduntil the acknowledgment signal is received since the transmission ofthe access signal (for example, until the RACH is received since theinitial transmission of the RACH), or the like.

For example, suppose that the transmission delay estimation informationtransmission condition is that the number of times of retransmission ofthe access signal required until the acknowledgment signal is receivedis four or more. At this time, when the number of times ofretransmission of the access signal is five with the communicationapparatus 2 ₁, the number of times of retransmission of the accesssignal is two with the communication apparatus 2 ₂, and the number oftimes of retransmission of the access signal is four with thecommunication apparatus 2 ₃, then each of the communication apparatus 2₁ and the communication apparatus 2 ₃ transmits the transmission delayestimation information to the radio communication network system 1because each of them meets the transmission delay estimation informationtransmission condition that the number of times of retransmission of theaccess signal required until the acknowledgment signal is received isfour or more. However, the communication apparatus 2 ₂ does not transmitthe transmission delay estimation information to the radio communicationnetwork system 1 because it does not meet the transmission delayestimation information transmission condition.

While conventionally, all of the communication apparatuses 2 ₁ to 2 ₃transmit the transmission delay estimation information at a time pointof having received the acknowledgment signal (ACK signal), thecommunication apparatus 2 ₁ and the communication apparatus 2 ₃, whichmeet the transmission delay estimation information transmissioncondition, transmit the transmission delay estimation information to theradio communication network system 1 in this invention. That is, thewireless resources for transmitting the transmission delay estimationinformation can be reduced to two thirds as compared with theconventional case.

Additionally, the transmission delay estimation information transmissioncondition may be preset to each communication apparatus, and aconfiguration may be made so that the radio communication network system1 transmits the condition to the communication apparatus and thecommunication apparatus sets the condition. The communication apparatusnotifies the radio communication network system of the utilizedtransmission delay estimation information transmission conditionsimultaneously with the transmission delay estimation information orseparately from it when a plurality of the transmission delay estimationinformation transmission conditions are specified and are preset to eachcommunication apparatus and each communication apparatus utilizes notall of them but one or more.

Further, upon paying attention to the communication apparatus to whichthe transmission delay estimation information transmission condition isapplied, the transmission delay estimation information transmissioncondition may be commonly applied to all of the communicationapparatuses that the radio communication network system 1 manages, maybe commonly applied only to the communication apparatuses meeting acertain condition, and may be separately applied to the communicationapparatuses that the radio communication network system 1 designates.

Hereinafter, the embodiment will be explained in details. Additionally,this embodiment will be described assuming that the system is a systemnow under consideration in the 3GPPLTE.

FIG. 5 is a conceptual diagram to which the present invention isapplied. In this system, a plurality of the base stations are presentadjacently to one another, a plurality of the mobile stations transmitor receive data on the downlink or the uplink to or from each of thebase stations, OFDM (Orthogonal Frequency Division Multiple Access) isused for the down link, and SC-FDMA is used for the uplink.Additionally, while it is assumed that the SC-FDMA is used for theuplink herein, the OFDM is also applicable. Furthermore, each of themobile stations and base stations realize functions to be describedbelow by a control program stored in a memory of each of the mobilestations and base stations.

The base station transmits on the down link at least a broadcast channelfor transmitting the broadcast information such as the systeminformation, a common pilot channel for transmitting the pilot signal(also referred to as reference signal), and a common channel fortransmitting the acknowledgment information etc. in response to uplinkdata transmission

Next, a configuration of the mobile station in the system mentionedabove is shown in FIG. 6 .

The mobile station of this embodiment is configured to include areception processing unit 11 for receiving a downlink signal andperforming a necessary reception process such as FFT (Fast FourierTransform), a signal separation unit 12 for separating signals inrespective channels from the received signal, a pilot signal measurementunit 13 for measuring a power intensity of the separated pilot signal, atransmission power calculation unit 14 for calculating a transmissionpower of the random access channel, an acknowledgment signaldetermination unit 15 for determining the acknowledgment signal receivedover the common channel, a transmission delay estimation informationgeneration unit 16 for generating the transmission delay estimationinformation, a buffer 17, a signal combining unit 18 for combining theuplink data with the control signal, a transmission processing unit 19for performing a process necessary for transmitting the signal, and atransmission determination unit 20 for determining the transmissiondelay estimation information transmission condition.

The signal separation unit 12 separates signals in respective channelsfrom the signal subjected to the reception process, and transmits thesignal of the common pilot channel to pilot signal measurement unit 13,the signal of the common pilot channel to the acknowledgment signaldetermination unit 15, and the signal of the broadcast channel to thepower calculation unit 14.

The pilot signal measurement unit 13 measures an average reception powerof the pilot signal in a predetermined cycle, and transmits ameasurement result to the transmission power calculation unit 14.

The transmission power calculation unit 14 calculates a transmissionpower of the random access channel from the transmission power of thecommon pilot channel notified by the broadcast channel, the poweroffset, and the average reception power of the pilot signal, andnotifies the transmission processing unit 19 of a calculation result.

The acknowledgment signal determination unit 15 determines whether theacknowledgment signal is received as acknowledgment information, andnotifies the transmission delay estimation information generation unit16 and the buffer 17 of a determination result.

The transmission delay estimation information generation unit 16generates the fixed transmission delay estimation information (thenumber of times of transmission or the number of times of retransmissionof the access signal and the like), and notifies the transmissiondetermination unit 20 of it.

The transmission determination unit 20 determines whether the mobilestation meets the transmission delay estimation information transmissioncondition, and transmits a determination result to the signal combiningunit 18 when it meets.

The buffer 17, upon receipt of the acknowledgment signal, destroys thecorresponding data, and transmits the corresponding data to the signalcombining unit 18 when it does not receive.

The signal combining unit 18 combines the data transmitted from thebuffer with the number-of-times information of transmission, andtransmits the resultant data to the transmission processing unit 19.

Continuously, a configuration of the base station in the systemmentioned above is shown in FIG. 7 .

The base station of this embodiment is configured to include a receptionprocessing unit 21, a decoding unit 22, an error determination unit 23,a signal separation unit 24 for separating the signal, a transmissiondelay estimation unit 25, a power offset control unit 26, a controlsignal generation unit 27, a signal combining unit 28, and atransmission processing unit 29.

The error determination unit 23 checks whether a data block includingthe data and the number-of-times information of transmission has noerror by a CRC added to the data block, and transmits the acknowledgmentsignal to the signal combining unit 28 and the data block to the signalseparation unit 24 when the base station can receive the data blockwithout an error.

The signal separation unit 24 transmits the transmission delayestimation information to the transmission delay estimation unit 25, andthe data to a higher layer.

The transmission delay estimation unit 25 collects the transmissiondelay estimation information of each mobile station, and records it in amemory not shown in the figure.

The power offset control unit 26 updates the power offset based upon thetransmission delay estimation information, and transmits an updateresult to the signal combining unit 28.

The control signal generation unit 27 generates the common pilot signaland the signal associated with other system control information, andtransmits the signals to the signal combining unit 28.

The signal combining unit 28 maps the transmitted signals on respectivechannels of the common pilot channel, the broadcast channel, and thecommon channel, code-multiplexes, spatially multiplexes,time-multiplexes, and frequency-multiplexes them, and transmits them tothe transmission processing unit 29.

Additionally, while the transmission delay estimation information isemployed for controlling the transmission power offset of the RACH inthis embodiment, the transmission delay estimation information can beutilized for the control of a transmission parameter of the RACH besidesit, for example, the control of a back-off parameter of the RACH.

Continuously, an operation between the mobile station and the basestation in the system mentioned above will be explained. FIG. 8 is asequence diagram in the case of commonly applying the transmission delayestimation information transmission condition to all of the mobilestations in the above-mentioned system.

At first, the mobile station transmits or receives data based upon thesystem information transmitted over the broadcast channel. Further, themobile station receives the common pilot channel in a predeterminedcycle to ensure synchronization of the downlink and measures a receptionquality of the common pilot channel (Step 10).

When the user data or the control signal (hereinafter, they are calleddata together) to be transmitted occurs to the mobile station, themobile station transmits the preamble using the random access channelthat is one of the wireless channels (Step 11). At this time, thetransmission power of the random access channel is decided based upon avalue indicated by the base station using the broadcast channel.

The base station notifies of the index (acknowledgment signal) of thecorrectly received preamble by the common channel (Step 12 and Step 14).

When the mobile station transmits the preamble over the random accesschannel, the mobile station receives the acknowledgment signalindicating that the preamble transmitted by its own station has beencorrectly received by an RA response including the acknowledgment signalover the common channel after a predetermined time, or retransmits thepreamble in a predetermined timing until a predetermined maximum numberof times of transmission is reached (Step 13). And, after receiving theacknowledgment signal, the mobile station transmits the data or thecontrol signal according to the random access response (RA Response)that is transmitted over the common channel. At this time, the presentinvention determines whether the mobile station satisfies thetransmission condition of the transmission delay estimation information.When the mobile station satisfies, the above mobile station transmitsthe transmission delay estimation information together with the data orthe control signal to the base station (step 15). When the mobilestation does not satisfy the transmission delay estimation informationtransmission condition, the above mobile station transmits only the dataor the control signal to the base station (step 15).

Additionally, a sequence diagram of FIG. 8 shows a situation in which amobile station A, which satisfies the transmission delay estimationinformation transmission condition, transmits the transmission delayestimation information together with the data to the base station, andon the other hand, the mobile station B, which does not satisfy thetransmission delay estimation information transmission condition,transmits only the data to the base station.

Next, the case of separately/selectively applying the transmission delayestimation information transmission condition to the mobile stationswill be explained. FIG. 9 is a sequence diagram in the case ofseparately/selectively applying the transmission delay estimationinformation transmission condition to the mobile stations in theabove-mentioned system.

A point in which the sequence diagram of FIG. 9 differs from that ofFIG. 8 is that when the base station correctly receives the preamble,the base station transmits a report request (Report request) togetherwith the acknowledgment signal to the mobile stations to which thetransmission delay estimation information transmission condition isapplied by using the RA Response that is transmitted over the commonchannel (Step 20), and the mobile station having received this judgeswhether it meets the transmission delay estimation informationtransmission condition, and transmits the transmission delay estimationinformation together with the data to the base station when it meets(Step 15).

Additionally, the Report request in the case of the separate control isnot always transmitted by using the RA Response, and it may be notifiedby using the downlink signal that is transmitted from base station tothe mobile station thereafter. For example, the downlink signal forContention Resolution adopted for the LTE, the downlink signal after theContention Resolution, or the like is thinkable.

FIG. 10 is a sequence diagram in the case of commonly applying thetransmission delay estimation information transmission condition to allof the mobile stations. A point in which the sequence of FIG. 10 differsfrom the sequences of FIG. 8 and FIG. 9 mentioned above is that themobile station, which meets the transmission delay estimationinformation transmission condition, transmits the transmission delayestimation information irrespectively of the reception of theacknowledgment signal.

At first, the mobile station transmits or receives the data based uponthe system information transmitted over the broadcast channel. Further,the mobile station receives the common pilot channel in a predeterminedcycle to ensure synchronization and measures a reception quality of thecommon pilot channel (Step 30).

When the user data or the control signal to be transmitted occurs, eachof the mobile stations A and B transmits the data and the preamble byusing the random access channel that is one of the wireless channels(Step 3-1). At this time, each of the mobile stations A and B transmitsthe transmission delay estimation information as well when it meets thetransmission delay estimation information transmission condition.

Each of the mobile stations A and B retransmits the preamble in apredetermined timing until it receives the acknowledgment signal (itsown station's preamble index) indicating that the preamble transmittedby its own station has been correctly received by the RA Response thatis transmitted over the common channel after a predetermined time (Step32 and Step 33).

Herein, the mobile station A, which has already met the transmissiondelay estimation information transmission condition at the time of thesecond-time transmission of the preamble, transmits the transmissiondelay estimation information together with the data and the preamble tothe base station (Step 33). On the other hand, the mobile station B,which has not met the transmission delay estimation informationtransmission condition yet at the time of the second-time transmissionof the preamble, transmits only the data and the preamble to the basestation (Step 33).

The base station notifies of the index (acknowledgment signal) of thecorrectly received preamble by the common channel (Step 32 and Step 34).

The mobile station A, upon receipt of the index of its own station'spreamble, transmits the data to the base station (Step 35). On the otherhand, the mobile station B, which was not able to receive the index ofits own station's preamble, executes the third-time transmission of thepreamble, and the mobile station B transmits the transmission delayestimation information together with the data and the preamble to thebase station because it has met the transmission delay estimationinformation transmission condition at the time of the third-timetransmission of the preamble (Step 35).

The mobile station B, upon receipt of the index of its own station'spreamble (Step 36), transmits the data to the base station (Step 37).

Additionally, the transmission delay estimation information transmissioncondition is commonly applied to all of the mobile stations in theexample of FIG. 10 mentioned above, and the situation is similar withthe case of the separate application like FIG. 9 . In this case, thebase station transmits the report request (Report request) by using theRA Response that is transmitted over the common channel, and the mobilestation having received the request transmits the transmission delayestimation information when it meets the transmission delay estimationinformation transmission condition.

Next, an operation of the mobile station in this embodiment will beexplained. In this operation, after the mobile station receives theacknowledgment signal, it is determined whether the mobile station meetsthe transmission condition of the transmission delay estimationinformation. FIG. 11 is an operational flowchart of the mobile stationin this embodiment.

The mobile station receives the system information that is transmittedover the broadcast channel (Step 100), receives the common pilot channelin a predetermined cycle to ensure synchronization of the downlinksignal, and measures a reception quality of the common pilot channel(Step 101).

When the data to be transmitted occurs to the mobile station, the mobilestation sets the number of times of transmission to one (1) (Step 103)and calculates the transmission power of the RACH (Step 104). And themobile station transmits the preamble over the RACH (Step 105).

The mobile station receives the RA Response that is transmitted over thecommon channel after a predetermined time (Step 106), and determineswhether the acknowledgment signal has been received (Step 107). When themobile station cannot receive the acknowledgment signal, the mobilestation determines whether the number of times of transmission of thepreamble is a maximum number of times of transmission (Step S108). Whenthe number of times of transmission is a maximum number of times oftransmission, the operation returns to the Step 100. When the number oftimes of transmission is not a maximum number of times of transmission,the mobile station adds one (1) to the number of times of transmission(Step 109), and the operation returns to the Step 104.

On the other hand, when the mobile station receives the acknowledgmentsignal, it is determined whether the mobile station meets thetransmission condition of the transmission delay estimation information(Step 110). When the mobile station has met the transmission conditionof the transmission delay estimation information, the mobile stationtransmits the transmission delay estimation information together withthe data to the base station (Step 111). Further, when the mobilestation has not met the transmission condition of the transmission delayestimation information, the mobile station transmits only the data tothe base station (Step 112).

Continuously, another operation of the mobile station in this embodimentwill be explained. In this operation, it is determined whether themobile station meets the transmission condition of the transmissiondelay estimation information at the time of transmitting the preamble ofthe RACH notwithstanding the reception of the acknowledgment signal.FIG. 12 is another operational flowchart of the mobile station in thisembodiment.

A point in which FIG. 12 differs from FIG. 11 is that it is determinedwhether the mobile station meets the transmission condition of thetransmission delay estimation information (Step 200) after calculatingthe transmission power of the RACH (Step 104), and yet beforetransmitting the preamble over the RACH (Step 105). And, the mobilestation, which has already met the transmission condition of thetransmission delay estimation information, transmits the transmissiondelay estimation information together with the preamble and the data tothe base station (Step 201). On the other hand, the mobile station,which has not met the transmission condition of the transmission delayestimation information yet, transmits only the preamble and the data tothe base station (Step 202).

The other steps of FIG. 12 are similar to those of FIG. 11 , so itsexplanation is omitted.

Additionally, in the foregoing explanation, each channel was describedby using general names, and a specific channel between UE (mobilestation) and eNodeB (base mobile) in the system of 3GPP LTE is shown inFIG. 13 .

That is, the broadcast channel for making a notification of the randomaccess parameter, the condition, and the situation from eNodeB (basemobile) to UE (mobile station) is BCCH with Logical layer, BCH or DL-SCHwith Transport layer. Further, the channel for making a random accessfrom the UE (mobile station) to the eNodeB (base mobile) is RACH withthe Transport layer. Further, the channel for making a random accessresponse from the eNodeB (base mobile) to the UE (mobile station) isCCCH with the Logical layer, and is DL-SCH with the Transport layer.Further, the channel for making a notification of the transmission delayestimation information from the UE (mobile station) to the eNodeB (basemobile) is CCCH or DCCH with the Logical layer, and is UL-SCH withTransport layer.

Additionally, while each unit of the foregoing mobile station and basestation is configured with hardware, one part or the entirety thereofcan be configured with CPU that operates under a program.

Next, specific examples of the present invention will be explained.

Example 1

In the example 1, the case that the transmission delay estimationinformation transmission condition is the number of times oftransmission of the access signal that is performed by the mobilestation, and is notified by the broadcast channel will be explained.Additionally, in the following explanation, the case that the mobilestation transmits the transmission delay estimation information when thenumber of times of transmission of the access signal by the mobilestation is larger than N=4 or is less than M=2 after receiving theacknowledgment is exemplified.

FIG. 14 is a diagram for explaining the example 1.

At first, the base station transmits the broadcast channel and thecommon pilot channel to the mobile stations A, B, and C.

When the data to be transmitted occurs, the mobile stations A, B, and Ctransmit the preamble using the random access channel that is one of thewireless channels.

The base station notifies of the index (acknowledgment signal) of thecorrectly received preamble by the common channel. At this time, themobile station C meets the transmission delay estimation informationtransmission condition that the number of times of transmission islarger than N=4 or is less than M=2 because the acknowledgment has beendetected at the time that the number of times of transmission of thepreamble is one (1). Thereupon, the mobile station C transmits thetransmission delay estimation information to the base station.

The mobile stations A and B, which cannot obtain the acknowledgment,transmit the preamble over the random access channel. Then, the mobilestation B does not meet the transmission delay estimation informationtransmission condition that the number of times of transmission islarger than N=4 or is less than M=2 because the acknowledgment has beendetected at the time that the number of times of transmission of thepreamble is two. Thus, the mobile station B does not transmit thetransmission delay estimation information to the base station.

The mobile stations A, which cannot obtain the acknowledgment, transmitthe preamble over the random access channel. Then, the mobile station Ameets the transmission delay estimation information transmissioncondition that the number of times of transmission is larger than N=4 oris less than M=2 because the acknowledgment has been detected at thetime that the number of times of transmission of the preamble is five.Thereupon, the mobile station A transmits the transmission delayestimation information to the base station.

In such a manner, the number of the mobile stations, which transmit thetransmission delay estimation information, can be reduced to two thirdsas compared with the conventional case that all of the mobile stationstransmit the transmission delay estimation information.

Example 2

In the example 2, the case that the transmission delay estimationinformation transmission condition is the number of times oftransmission of the access signal that is performed by the mobilestation, and is notified by the broadcast channel, and yet that thetarget mobile station is a mobile station having received the Reportrequest, being a separate control, will be explained. Additionally, inthe following explanation, the case that the mobile station, which hasthe number of times of transmission of the access signal larger than N=4or less than M=2 after receiving the acknowledgment, and yet hasreceived the Report request, transmits the transmission delay estimationinformation is exemplified.

FIG. 15 is a diagram for explaining the example 2.

At first, the base station transmits the broadcast channel and thecommon pilot channel to the mobile stations A, B, and C.

When the data to be transmitted occurs, the mobile stations A, B, and Ctransmit the preamble using the random access channel that is one of thewireless channels.

The base station notifies of the index (acknowledgment signal) of thecorrectly received preamble by the common channel. At this time, themobile station C has the number of times of transmission larger than N=4or less than M=2 because the acknowledgment has been detected at thetime that the number of times of transmission of the preamble is one(1), but has not received the Report request. Thereupon, the mobilestation C does not transmit the transmission delay estimationinformation to the base station.

The mobile stations A and B, which cannot obtain the acknowledgment,transmit the preamble over the random access channel. Then, the mobilestation B does not meet the transmission delay estimation informationtransmission condition that the number of times of transmission islarger than N=4 or is less than M=2 because the acknowledgment has beendetected at the time that the number of times of transmission of thepreamble is two. Thus, the mobile station B does not transmit thetransmission delay estimation information to the base station.

The mobile station A, which cannot obtain the acknowledgment, transmitsthe preamble over the random access channel. Then, the mobile station Ameets the transmission delay estimation information transmissioncondition because the mobile station A has the number of times oftransmission larger than N=4 or less than M=2 due to the detection ofthe acknowledgment at the time that the number of times of transmissionof the preamble is five, and yet received the Report request. Thereupon,the mobile station A transmits the transmission delay estimationinformation to the base station.

In such a manner, the number of the mobile stations, which transmit thetransmission delay estimation information, can be reduced to two thirdsas compared with the conventional case that all of the mobile stationstransmit the transmission delay estimation information.

While it was assumed that the transmission delay estimation informationtransmission condition was notified by the broadcast channel in theexample 2, there exists the method as well of notifying of it togetherwith the Report request.

Example 3

In the example 3, the case that the transmission delay estimationinformation transmission condition is the transmission power of therandom access channel will be explained. Additionally, in the followingexplanation, the case of transmitting the transmission delay estimationinformation when the transmission power of the random access channel ofthe mobile station is less than a maximum value after receiving theacknowledgment is exemplified.

FIG. 16 is a diagram for explaining the example 3.

At first, it is assumed that when the transmission power of the randomaccess channel of the mobile station is P_Tx, the transmission powerP_Tx is controlled by the following equation.P_Tx=CPICH_Tx−CPICH_Rx+PO+ΔP×(number of times of transmission−1) [dBm]

Wherein CPICH_Tx is the transmission power of the common pilot channel,CPICH_Rx is the reception power of the common pilot channel, PO is thepower offset, and ΔP is the ramping step size, and it is assumed thateach of them is common to the mobile stations.

Herein, each of the mobile stations A and B increases the transmissionpower P_Tx by ΔP whenever it transmits the random access channel asshown in FIG. 16 .

In this case, at the time of having received the acknowledgment, thetransmission power P_Tx of the mobile stations A is the maximumtransmission power. Thus, the mobile station A does not transmit thetransmission delay estimation information to the base station becausethe mobile station A does not meet the transmission delay estimationinformation transmission condition that the transmission power of therandom access channel of the mobile station is less than the maximum.

On the other hand, at the time that the mobile station B has receivedthe acknowledgment, the transmission power P_Tx of the mobile stations Bis less than the maximum transmission power. Thus, the mobile station Btransmits the transmission delay estimation information to the basestation because the mobile station B meets the transmission delayestimation information transmission condition that the transmissionpower of the random access channel of the mobile station is less thanthe maximum.

Example 4

In the example 4, the case that the transmission delay estimationinformation transmission condition is a probability control utilizing atarget probability P (P is a real number equal to or more than zero andless than 1) designated by the base station will be explained.

At first, when the mobile station transmits the random access channel,and receives the acknowledgment, the mobile station creates uniformdistribution random numbers “rand” equal to or more than zero and lessthan 1. The mobile station transmits the transmission delay estimationinformation and the data to the base station when the “rand” is largerthan the probability P, and otherwise transmits only the data withouttransmitting the transmission delay estimation information.

Example 5

In the example 5, the case that the transmission delay estimationinformation transmission condition is a traffic amount of the preambleof the random access channel and whether or not to transmit thetransmission delay estimation information is notified by the broadcastchannel will be explained.

In this example, the base station monitors a traffic amount of thepreamble of the random access channel, and instructs each mobile stationto transmit the transmission delay estimation information by thebroadcast channel when the traffic amount exceeds a predeterminedthreshold T.

Each mobile station, upon receipt of the instruction for transiting thetransmission delay estimation information by the broadcast channel,transmits the transmission delay estimation information together withthe data after receiving the acknowledgment signal.

Next, a specific operation of the example 5 will be explained byemploying FIG. 17 . FIG. 17 is a sequence diagram illustrating anoperation of the example 5.

At first, the base station transmits the broadcast channel and thecommon pilot channel to the mobile stations A, B, and C.

When the data to be transmitted occurs, the mobile stations A, B, and Ctransmit the preamble using the random access channel that is one of thewireless channels. In an example of FIG. 17 , the mobile stations A andB transmit the preamble using the random access channel.

The base station monitors a traffic amount of the preamble of the randomaccess channel, and the base station notifies of the index(acknowledgment signal) of the correctly received preamble by the commonchannel. In an example of FIG. 16 , the mobile station A transmits thepreamble over the random access channel again because it was not able todetect the acknowledgment signal. On the other hand, the mobile stationB transmits the data because it was able to detect the acknowledgment.Further, the mobile station C transmits the preamble over the randomaccess channel because the data to be transmitted has occurred. And, thebase station was not able to detect the preamble of the mobile stationsA and C, so the mobile stations A and C cannot detect the acknowledgmentsignal.

When the traffic amount exceeds a predetermined threshold T as a resultof monitoring the traffic amount of the preamble of the random accesschannel, the base station instructs each mobile station to transmit thetransmission delay estimation information by the broadcast channel. Ainstruction for transmitting the transmission delay estimationinformation or not is made with a transmission frequency of thebroadcast channel or the integer multiples thereof.

The mobile station having received an instruction for transmitting thetransmission delay estimation information by the broadcast channeltransmits the transmission delay estimation information together withthe data after receiving the acknowledgment signal. In an example ofFIG. 17 , the mobile stations A and B, which have received theacknowledgment signal after receiving the instruction for transmittingthe transmission delay estimation information, transmits thetransmission delay estimation information together with data.

When the traffic amount becomes smaller than a predetermined threshold Tas a result of monitoring the traffic amount of the preamble of therandom access channel, the base station notifies each mobile stationthat the transmission delay estimation information does not need to betransmitted by using the broadcast channel.

The mobile stations A, B, and C, which have been notified that thetransmission delay estimation information does not need to betransmitted, do not transmit the transmission delay estimationinformation.

Additionally, while as shown in an exemplification 1 of FIG. 18 , thecase of causing the mobile station to transmit the transmission delayestimation information when the traffic amount exceeds a predeterminedthreshold T as a result of monitoring the traffic amount of the preambleof the random access channel was explained in the examples mentionedabove, a scheme of causing the mobile station to transmit thetransmission delay estimation information is mot limited hereto. Forexample, as shown in an exemplification 2 of FIG. 18 , a configurationin which an upper-limit threshold and a lower-limit threshold are set,the mobile station is caused to transmit the transmission delayestimation information when the traffic amount exceeds an upper-limitthreshold, and is caused not to transmit the transmission delayestimation information when the traffic amount has become smaller thanan lower-limit threshold may be made.

Example 6

In the example 6, the case that the transmission delay estimationinformation transmission condition is judged dependent upon anapplication, and in particular, the case that the application is ahandover will be explained.

FIG. 19 is a diagram for explaining the example 6.

In FIG. 19 , a terminal A, which stays in a cell 1, makes an access onlyto a base station a. In this case, the terminal A does not notify of thetransmission delay estimation information. On the other hand, a terminalB performs a handover from the cell 1 to a cell 21 and makes an accessto a base station b. In this case, the terminal B notifies the basestation B of the transmission delay estimation information. That is, theterminal, which performs a handover, notifies of the transmission delayestimation information, and the terminal, which does not perform ahandover, does not notify of the transmission delay estimationinformation.

A specific operation will be explained by employing FIG. 20 .Additionally, in FIG. 19 , the case of the 3GPP LTE is imagined.

At first, UE B (mobile station) transmits Measurement report to aneNodeB a (base station a). The NodeB a having received the Measurementreport makes a Handover request for an NodeB b.

The NodeB b having received the Handover request transmits a response(ACK) to the Handover request to the NodeB a. At this time, the NodeB btransmits the response including the Report request, being aninstruction for causing the UE B to notify of the transmission delayestimation information.

The NodeB a having received the response (ACK) to the Handover requesttransmits Handover command to the UE B. At this time, the NodeB atransmits the command including the Report request.

The UE B having received the Handover command transmits the randomaccess to the NodeB b. And, the NodeB b having received the randomaccess transmits a response to the random access to the UE B.

The UE B having received the response to the random access transmitsHandover confirm and the transmission delay estimation information tothe NodeB b.

Continuously, another specific operation will be explained by employingFIG. 21 . Additionally, in FIG. 21 as well, the case of the 3GPP LTE isimagined.

At first, the UE B (mobile station) transmits the Measurement report tothe eNodeB a (base station a). The NodeB a having received theMeasurement report makes a Handover request for the NodeB b.

The NodeB b having received the Handover request transmits a response(ACK) to the Handover request to the NodeB a.

The NodeB a having received the response (ACK) to the Handover requesttransmits the Handover command to the UE B.

The UE B having received the Handover command transmits the randomaccess to the NodeB b. And, the NodeB b having received the randomaccess transmits a response to the random access to the UE B. At thistime, the NodeB b transmits the Report request as well.

The UE B having received the response to the random access transmits theHandover confirm and the transmission delay estimation information tothe NodeB b.

While the transmission delay estimation information was transmittedsimultaneously with the Handover confirm in the above-mentioned example,the transmission delay estimation information may be transmitted aftertransmitting the Handover confirm.

The 1st mode of the present invention is characterized in that a radiocommunication system comprising a communication apparatus and a radiocommunication network system, wherein the communication apparatuscomprises a transmission delay estimation information transmission unitfor transmitting transmission delay estimation information to the radiocommunication network system when a transmission condition oftransmission delay estimation information is met.

The 2nd mode of the present invention, in the above-mentioned mode, ischaracterized in that said transmission delay estimation informationtransmission unit transmits the transmission delay estimationinformation when the transmission condition of the transmission delayestimation information is met at the moment of transmitting an accesssignal.

The 3rd mode of the present invention, in the above-mentioned mode, ischaracterized in that said transmission delay estimation informationtransmission unit transmits the transmission delay estimationinformation when the transmission condition of the transmission delayestimation information is met after receiving an acknowledgment signal.

The 3rd mode of the present invention, in the above-mentioned mode, ischaracterized in that the radio communication system comprising a commoncontrol unit for causing the communication apparatus to commonlytransmit the transmission delay estimation information.

The 4th mode of the present invention, in the above-mentioned mode, ischaracterized in that the radio communication system comprising aseparate control unit for causing the communication apparatus toseparately transmit the transmission delay estimation information.

The 5th mode of the present invention, in the above-mentioned mode, ischaracterized in that said radio communication network system comprisesat least a base station.

The 7th mode of the present invention, in the above-mentioned mode, ischaracterized in that said transmission condition of the transmissiondelay estimation information is a condition based upon the number oftimes of transmission of the access signal.

The 8th mode of the present invention, in the above-mentioned mode, ischaracterized in that said transmission condition of the transmissiondelay estimation information is a condition based upon the number oftimes of retransmission of the access signal.

The 9th mode of the present invention, in the above-mentioned mode, ischaracterized in that said transmission condition of the transmissiondelay estimation information is a condition based upon a transmissionpower required at the time of completing the transmission.

The 10th mode of the present invention, in the above-mentioned mode, ischaracterized in that said transmission condition of the transmissiondelay estimation information is a condition based upon a reportprobability that said communication apparatus is caused to report saidtransmission delay information.

The 11th mode of the present invention, in the above-mentioned mode, ischaracterized in that said transmission condition of the transmissiondelay estimation information is a condition based upon a traffic of theaccess signal or all of traffics.

The 12th mode of the present invention, in the above-mentioned mode, ischaracterized in that said transmission condition of the transmissiondelay estimation information is a condition based upon a path loss.

The 13th mode of the present invention, in the above-mentioned mode, ischaracterized in that said transmission condition of the transmissiondelay estimation information is a condition based upon a time elapseduntil an acknowledgment signal is received since the transmission of theaccess signal.

The 14th mode of the present invention, in the above-mentioned mode, ischaracterized in that said transmission condition of the transmissiondelay estimation information is a condition based upon an application ofthe access signal.

The 15th mode of the present invention, in the above-mentioned mode, ischaracterized in that a plurality of said transmission conditions of thetransmission delay estimation information are combined and employed.

The 16th mode of the present invention, in the above-mentioned mode, ischaracterized in that said transmission delay estimation information isat least one of the number of times of transmission or the number oftimes of retransmission of the access signal, a time elapsed sinceinitial transmission of the access signal, a timing of the initialtransmission of the access signal, a back-off period required fortransmitting the access signal, a value obtained by deducting theback-off period from a period required for transmitting the accesssignal, the number of times of power ramping required for transmittingthe access signal, and the number of times of power ramping cyclerequired for transmitting the access signal.

The 17th mode of the present invention is characterized in that acommunication apparatus, comprising a transmission delay estimationinformation transmission unit for transmitting transmission delayestimation information to a radio communication network system when atransmission condition of transmission delay estimation information ismet.

The 18th mode of the present invention, in the above-mentioned mode, ischaracterized in that said transmission delay estimation informationtransmission unit transmits the transmission delay estimationinformation when the transmission condition of the transmission delayestimation information is met at the moment of transmitting an accesssignal.

The 19th mode of the present invention, in the above-mentioned mode, ischaracterized in that said transmission delay estimation informationtransmission unit transmits the transmission delay estimationinformation when the transmission condition of the transmission delayestimation information is met after receiving an acknowledgment signal.

The 20th mode of the present invention, in the above-mentioned mode, ischaracterized in that said transmission condition of the transmissiondelay estimation information is a condition based upon the number oftimes of transmission of the access signal.

The 21st mode of the present invention, in the above-mentioned mode, ischaracterized in that said transmission condition of the transmissiondelay estimation information is a condition based upon the number oftimes of retransmission of the access signal.

The 22nd mode of the present invention, in the above-mentioned mode, ischaracterized in that said transmission condition of the transmissiondelay estimation information is a condition based upon a transmissionpower required at the time of completing the transmission.

The 23rd mode of the present invention, in the above-mentioned mode, ischaracterized in that said transmission condition of the transmissiondelay estimation information is a condition based upon a reportprobability that said communication apparatus is caused to report saidtransmission delay information.

The 24th mode of the present invention, in the above-mentioned mode, ischaracterized in that said transmission condition of the transmissiondelay estimation information is a condition based upon a traffic of theaccess signal or all of traffics.

The 25th mode of the present invention, in the above-mentioned mode, ischaracterized in that said transmission condition of the transmissiondelay estimation information is a condition based upon a path loss.

The 26th mode of the present invention, in the above-mentioned mode, ischaracterized in that said transmission condition of the transmissiondelay estimation information is a condition based upon a time elapseduntil an acknowledgment signal is received since the transmission of theaccess signal.

The 27th mode of the present invention, in the above-mentioned mode, ischaracterized in that said transmission condition of the transmissiondelay estimation information is a condition based upon an application ofthe access signal.

The 28th mode of the present invention, in the above-mentioned mode, ischaracterized in that a plurality of said transmission conditions of thetransmission delay estimation information are combined and employed.

The 29th mode of the present invention, in the above-mentioned mode, ischaracterized in that said transmission delay estimation information isat least one of the number of times of transmission or the number oftimes of retransmission of the access signal, a time elapsed sinceinitial transmission of the access signal, a timing of the initialtransmission of the access signal, a back-off period required fortransmitting the access signal, a value obtained by deducting theback-off period from a period required for transmitting the accesssignal, the number of times of power ramping required for transmittingthe access signal, and the number of times of power ramping cyclerequired for transmitting the access signal.

The 30th mode of the present invention is characterized in that a radiocommunication network system in a communication system for transmittingtransmission delay estimation information when a communication apparatusmeets a transmission condition of the transmission delay estimationinformation, said radio communication network system comprising a commoncontrol unit for causing the communication apparatus to commonlytransmit the transmission delay estimation information.

The 31st mode of the present invention is characterized in that a radiocommunication network system in a communication system for transmittingtransmission delay estimation information when a communication apparatusmeets a transmission condition of the transmission delay estimationinformation, said radio communication network system comprising aseparate control unit for causing the communication apparatus toseparately transmit the transmission delay estimation information.

The 32nd mode of the present invention is characterized in that a radiocommunication method, wherein a communication apparatus transmitstransmission delay estimation information to a radio communicationnetwork system when a transmission condition of the transmission delayestimation information is met.

The 33rd mode of the present invention, in the above-mentioned mode, ischaracterized in that the communication apparatus transmits thetransmission delay estimation information when the transmissioncondition of the transmission delay estimation information is met at themoment of transmitting an access signal.

The 34th mode of the present invention, in the above-mentioned mode, ischaracterized in that the communication apparatus transmits thetransmission delay estimation information when the transmissioncondition of the transmission delay estimation information is met afterreceiving an acknowledgment signal.

The 35th mode of the present invention, in the above-mentioned mode, ischaracterized in that the radio communication network system causes thecommunication apparatus to commonly transmit the transmission delayestimation information.

The 36th mode of the present invention, in the above-mentioned mode, ischaracterized in that the radio communication network system causes thecommunication apparatus to separately transmit the transmission delayestimation information.

The 37th mode of the present invention, in the above-mentioned mode, ischaracterized in that the radio communication network system comprisesat least a base station.

The 38th mode of the present invention, in the above-mentioned mode, ischaracterized in that said transmission condition of the transmissiondelay estimation information is a condition based upon the number oftimes of transmission of the access signal.

The 39th mode of the present invention, in the above-mentioned mode, ischaracterized in that said transmission condition of the transmissiondelay estimation information is a condition based upon the number oftimes of retransmission of the access signal.

The 40th mode of the present invention, in the above-mentioned mode, ischaracterized in that said transmission condition of the transmissiondelay estimation information is a condition based upon a transmissionpower required at the time of completing the transmission.

The 41st mode of the present invention, in the above-mentioned mode, ischaracterized in that said transmission condition of the transmissiondelay estimation information is a condition based upon a reportprobability that said communication apparatus is caused to report saidtransmission delay estimation information.

The 42nd mode of the present invention, in the above-mentioned mode, ischaracterized in that said transmission condition of the transmissiondelay estimation information is a condition based upon a traffic of theaccess signal or all of traffics.

The 43rd mode of the present invention, in the above-mentioned mode, ischaracterized in that said transmission condition of the transmissiondelay estimation information is a condition based upon a path loss.

The 44th mode of the present invention, in the above-mentioned mode, ischaracterized in that said transmission condition of the transmissiondelay estimation information is a condition based upon a time elapseduntil an acknowledgment signal is received since the transmission of theaccess signal.

The 45th mode of the present invention, in the above-mentioned mode, ischaracterized in that said transmission condition of the transmissiondelay estimation information is a condition based upon an application ofthe access signal.

The 46th mode of the present invention, in the above-mentioned mode, ischaracterized in that a plurality of said transmission conditions of thetransmission delay estimation information are combined and employed.

The 47th mode of the present invention, in the above-mentioned mode, ischaracterized in that said transmission delay estimation information isat least one of the number of times of transmission or the number oftimes of retransmission of the access signal, a time elapsed sinceinitial transmission of the access signal, a timing of the initialtransmission of the access signal, a back-off period required fortransmitting the access signal, a value obtained by deducting theback-off period from a period required for transmitting the accesssignal, the number of times of power ramping required for transmittingthe access signal, and the number of times of power ramping cyclerequired for transmitting the access signal.

The 48th mode of the present invention is characterized in that aprogram for causing a communication apparatus to execute a process oftransmitting transmission delay estimation information to a radiocommunication network system when a transmission condition of thetransmission delay estimation information is met.

The 49th mode of the present invention is characterized in that aprogram of a radio communication network system in a communicationsystem for transmitting transmission delay estimation information when acommunication apparatus meets a transmission condition of thetransmission delay estimation information is met, said program causingthe radio communication network system to execute a process of causingthe communication apparatus to commonly transmit the transmission delayestimation information.

The 50th mode of the present invention is characterized in that aprogram of a radio communication network system in a communicationsystem for transmitting transmission delay estimation information when acommunication apparatus meets a transmission condition of thetransmission delay estimation information, said program causing theradio communication network system to execute a process of causing thecommunication apparatus to separately transmit the transmission delayestimation information.

Above, although the present invention has been particularly describedwith reference to the preferred embodiments, examples, and modesthereof, it should be readily apparent to those of ordinary skill in theart that the present invention is not always limited to theabove-mentioned embodiment and modes, and changes and modifications inthe form and details may be made without departing from the sprit andscope of the invention.

This application is based upon and claims the benefit of priority fromJapanese patent application No. 2008-57726, filed on Mar. 7, 2008, thedisclosure of which is incorporated herein in its entirety by reference.

The invention claimed is:
 1. A user equipment comprising: a transmitterconfigured to transmit a preamble using a random access channel; and areceiver configured to receive a random access response, wherein thereceiver is configured to receive, from a base station, a reportrequest, wherein the transmitter is configured to transmit, to the basestation, information in response to reception of the report request,wherein the information indicates a number of preamble transmissions,wherein the report request is different from the random access response,wherein the report request is dedicated to the user equipment, andwherein the information is transmitted using an uplink channel fordedicated control.
 2. The user equipment according to claim 1, whereinthe transmitter is configured to transmit, to the base station, theinformation in a case where the user equipment receives the reportrequest and the number of preamble transmissions is less than apredetermined number.
 3. The user equipment according to claim 1,wherein the information is transmitted in a case where the userequipment receives the report request and the number of preambletransmissions is less than a predetermined number.
 4. A method for auser equipment, the method comprising: transmitting a preamble using arandom access channel; receiving a random access response; receiving,from a base station, a report request; and transmitting, to the basestation, information in response to reception of the report request,wherein the information indicates a number of preamble transmissions,wherein the report request is different from the random access response,wherein the report request is dedicated to the user equipment, andwherein the information is transmitted using an uplink channel fordedicated control.
 5. The method according to claim 4, wherein theinformation is transmitted in a case where the user equipment receivesthe report request and the number of preamble transmissions is less thana predetermined number.
 6. The method according to claim 4, wherein thetransmitting, to the base station, the information in response to thereception of the report request comprises transmitting the informationin a case where the number of preamble transmissions is less than apredetermined number.
 7. The method according to claim 4, wherein thetransmitting, to the base station, the information in response to thereception of the report request is performed in a case where the numberof preamble transmissions is less than a predetermined number.
 8. Acommunication apparatus comprising: a receiver configured to receive apreamble; and a transmitter configured to transmit a random accessresponse, wherein the transmitter is configured to transmit, to a userequipment, a report request, wherein the receiver is configured toreceive, from the user equipment, information in a case where the reportrequest is transmitted, wherein the information indicates a number ofpreamble transmissions, wherein the report request is different from therandom access response, wherein the report request is dedicated to theuser equipment, and wherein the information is received using an uplinkchannel for dedicated control.
 9. The communication apparatus accordingto claim 8, wherein the report request is a request for the userequipment to report the information.
 10. The communication apparatusaccording to claim 8, wherein the report request is used by thecommunication apparatus to request the user equipment to report theinformation.
 11. A method for a communication apparatus, the methodcomprising: receiving a preamble; transmitting a random access response;transmitting, to a user equipment, a report request; and receiving, fromthe user equipment, information in a case where the report request istransmitted, wherein the information indicates a number of preambletransmissions, wherein the report request is different from the randomaccess response, wherein the report request is dedicated to the userequipment, and wherein the information is received using an uplinkchannel for dedicated control.
 12. The method according to claim 11,wherein the report request is a request for the user equipment to reportthe information.
 13. The method according to claim 11, wherein thereport request is used by the communication apparatus to request theuser equipment to report the information.